Entomological risk assessment for transmission of arboviral diseases by Aedes mosquitoes in a domestic and forest site in Accra, Ghana.

Dengue, Zika and chikungunya are Aedes-borne viral diseases that have become great global health concerns in the past years. Several countries in Africa have reported outbreaks of these diseases and despite Ghana sharing borders with some of these countries, such outbreaks are yet to be detected. Viral RNA and antibodies against dengue serotype-2 have recently been reported among individuals in some localities in the regional capital of Ghana. This is an indication of a possible silent transmission ongoing in the population. This study, therefore, investigated the entomological transmission risk of dengue, Zika and chikungunya viruses in a forest and domestic population in the Greater Accra Region, Ghana. All stages of the Aedes mosquito (egg, larvae, pupae and adults) were collected around homes and in the forest area for estimation of risk indices. All eggs were hatched and reared to larvae or adults for morphological identification together with larvae and adults collected from the field. The forest population had higher species richness with 7 Aedes species. The predominant species of Aedes mosquitoes identified from both sites was Aedes aegypti (98%). Aedes albopictus, an important arbovirus vector, was identified only in the peri-domestic population at a prevalence of 1.5%, significantly higher than previously reported. All risk indices were above the WHO threshold except the House Index for the domestic site which was moderate (19.8). The forest population recorded higher Positive Ovitrap (34.2% vs 26.6%) and Container (67.9% vs 36.8%) Indices than the peri-domestic population. Although none of the mosquito pools showed the presence of dengue, chikungunya or Zika viruses, all entomological risk indicators showed that both sites had a high potential arboviral disease transmission risk should any of these viruses be introduced. Continuous surveillance is recommended in these and other sites in the Metropolis to properly map transmission risk areas to inform outbreak preparedness strategies.

Perfil das notificações de dengue e febre chikungunya em Cabo Frio/Rj, 2014-2019 / Profile of dengue and chikungunya notifications in Cabo Frio/Rj, 2014-2019 / Perfil de las notificaciones de dengue y chikungunya en Cabo Frio/Rj, 2014-2019

Introdução: De acordo com a literatura científica, diagnósticos clínicos diferenciais de arboviroses representam uma dificuldade no que tange à dengue, na medida em que está no Brasil há muitos anos, o que acarreta em ser a arbovirose mais conhecida no país. As notificações de arboviroses se tornaram obrigatórias para inserção no SINAN, possibilitando a construção de perfis demográficos e o cálculo de incidências a partir de informações específicas para estas doenças. No que tange à dengue, a epidemia deste agravo ocorre no país desde 1986, evidenciando falhas na prevenção, relacionadas a aspectos socioeconômicos e ambientais. Objetivo: analisar perfis das notificações de dengue e febre de chikungunya dos casos notificados no município de Cabo Frio. Metodologia: Trata-se de estudo transversal e descritivo, com uso de dados secundários do SINAN referentes a casos de arboviroses no município de Cabo Frio/RJ. Foram observadas variáveis relacionadas ao sexo, escolaridade, raça/cor e critérios de confirmação, além do grau de completude. Resultados: Foram notificados 8.777 casos suspeitos de arboviroses, incluindo-se 1.367 notificações (15,57%) referentes à febre de chikungunya e 1.986 (22,63%), à dengue. Em relação ao desfecho, 1186 casos (51,45%) foram fechados como inconclusivos e 344 destes (14,92%) foram descartados como arboviroses. Dentre os inconclusivos, 943 (79,51%) eram referentes à notificação de dengue, idem para os 277 casos descartados (80,52%). Conclusão: Observou-se baixa taxa de completude nas fichas de notificação, explicada pelo baixo número de recursos humanos e pela insuficiente infraestrutura. Sugere-se a interação de diferentes profissionais e pesquisadores, facilitando a compreensão da complexa dinâmica das arboviroses em questão.

Introduction: According to the scientific literature, differential clinical diagnoses of arboviruses represent a difficulty with regard to dengue, as it has been present in Brazil for many years, which makes it the most well-known arbovirus in the country. Notifications of arboviruses became mandatory for inclusion in SINAN, enabling the construction of demographic profiles and the calculation of incidences based on specific information for these diseases. With regard to dengue, the epidemic of this disease has occurred in the country since 1986, showing failures in prevention, related to socioeconomic and environmental aspects. Objective: to analyze profiles of notifications of dengue and chikungunya fever of cases notified in the municipality of Cabo Frio. Methodology: This is a cross-sectional and descriptive study, using secondary data from SINAN regarding cases of arboviruses in the municipality of Cabo Frio/RJ. Variables related to sex, education, race/color and confirmation criteria were observed, in addition to the degree of completeness. Results: 8,777 suspected cases of arboviruses were reported, including 1,367 reports (15.57%) referring to chikungunya fever and 1,986 (22.63%) to dengue fever. Regarding the outcome, 1186 cases (51.45%) were closed as inconclusive and 344 of these (14.92%) were discarded as arboviruses. Among the inconclusive ones, 943 (79.51%) were related to dengue notification, the same for the 277 discarded cases (80.52%). Conclusion: A low completeness rate was observed in the notification forms, explained by the low number of human resources and insufficient infrastructure. It is suggested the interaction of different professionals and researchers, facilitating the understanding of the complex dynamics of the arboviruses in question.

Introducción: Según la literatura científica, los diagnósticos clínicos diferenciales de los arbovirus representan una dificultad con respecto al dengue, ya que está presente en Brasil desde hace muchos años, lo que lo convierte en el arbovirus más conocido en el país. Las notificaciones de arbovirus pasaron a ser obligatorias para su inclusión en el SINAN, lo que permitió la construcción de perfiles demográficos y el cálculo de incidencias a partir de información específica de estas enfermedades. Con respecto al dengue, la epidemia de esta enfermedad se presenta en el país desde 1986, mostrando fallas en la prevención, relacionadas con aspectos socioeconómicos y ambientales. Objetivo: analizar perfiles de notificaciones de dengue y fiebre chikungunya de los casos notificados en el municipio de Cabo Frio. Metodología: Se trata de un estudio transversal y descriptivo, utilizando datos secundarios del SINAN sobre casos de arbovirus en el municipio de Cabo Frio/RJ. Se observaron variables relacionadas con el sexo, escolaridad, raza/color y criterios de confirmación, además del grado de completitud. Resultados: se notificaron 8.777 casos sospechosos de arbovirus, de los cuales 1.367 (15,57%) se referían a fiebre chikungunya y 1.986 (22,63%) a dengue. En cuanto al resultado, 1186 casos (51,45%) se cerraron como no concluyentes y 344 de estos (14,92%) se descartaron como arbovirus. Entre los inconclusos, 943 (79,51%) estaban relacionados con la notificación de dengue, lo mismo para los 277 casos descartados (80,52%). Conclusión: Se observó un bajo índice de completitud en los formularios de notificación, explicado por el bajo número de recursos humanos y la infraestructura insuficiente. Se sugiere la interacción de diferentes profesionales e investigadores, facilitando la comprensión de la compleja dinámica de los arbovirus en cuestión.

Simple, sensitive, and cost-effective detection of wAlbB Wolbachia in Aedes mosquitoes, using loop mediated isothermal amplification combined with the electrochemical biosensing method.

BACKGROUND: Wolbachia is an endosymbiont bacterium generally found in about 40% of insects, including mosquitoes, but it is absent in Aedes aegypti which is an important vector of several arboviral diseases. The evidence that Wolbachia trans-infected Ae. aegypti mosquitoes lost their vectorial competence and became less capable of transmitting arboviruses to human hosts highlights the potential of using Wolbachia-based approaches for prevention and control of arboviral diseases. Recently, release of Wolbachia trans-infected Ae. aegypti has been deployed widely in many countries for the control of mosquito-borne viral diseases. Field surveillance and monitoring of Wolbachia presence in released mosquitoes is important for the success of these control programs. So far, a number of studies have reported the development of loop mediated isothermal amplification (LAMP) assays to detect Wolbachia in mosquitoes, but the methods still have some specificity and cost issues. METHODOLOGY/PRINCIPAL FINDINGS: We describe here the development of a LAMP assay combined with the DNA strand displacement-based electrochemical sensor (BIOSENSOR) method to detect wAlbB Wolbachia in trans-infected Ae. aegypti. Our developed LAMP primers used a low-cost dye detecting system and 4 oligo nucleotide primers which can reduce the cost of analysis while the specificity is comparable to the previous methods. The detection capacity of our LAMP technique was 1.4 nM and the detection limit reduced to 2.2 fM when combined with the BIOSENSOR. Our study demonstrates that a BIOSENSOR can also be applied as a stand-alone method for detecting Wolbachia; and it showed high sensitivity when used with the crude DNA extracts of macerated mosquito samples without DNA purification. CONCLUSIONS/SIGNIFICANCE: Our results suggest that both LAMP and BIOSENSOR, either used in combination or stand-alone, are robust and sensitive. The methods have good potential for routine detection of Wolbachia in mosquitoes during field surveillance and monitoring of Wolbachia-based release programs, especially in countries with limited resources.

Determinants of Aedes mosquito density as an indicator of arbovirus transmission risk in three sites affected by co-circulation of globally spreading arboviruses in Colombia, Ecuador and Argentina.

BACKGROUND: The global impact of Zika virus in Latin America has drawn renewed attention to circulating mosquito-borne viruses in this region, such as dengue and chikungunya. Our objective was to assess socio-ecological factors associated with Aedes mosquito vector density as a measure of arbovirus transmission risk in three cities of potentially recent Zika virus introduction: Ibagué, Colombia; Manta, Ecuador; and Posadas, Argentina, in order to inform disease mitigation strategies. METHODS: We sampled Aedes mosquito populations in a total of 1086 households, using indoor and peridomestic mosquito collection methods, including light traps, resting traps, traps equipped with chemical attractant and aspirators. For each sampled household, we collected socio-economic data using structured questionnaires and data on microenvironmental conditions using iButton data loggers. RESULTS: A total of 3230 female Aedes mosquitoes were collected, of which 99.8% were Aedes aegypti and 0.2% were Aedes albopictus. Mean female Aedes mosquito density per household was 1.71 (standard deviation: 2.84). We used mixed-effects generalized linear Poisson regression analyses to identify predictors of Aedes density, using month, neighborhood and country as random-effects variables. Across study sites, the number of household occupants [incidence rate ratio (IRR): 1.08, 95% confidence interval (CI): 1.01-1.14], presence of entry points for mosquitoes into the household (IRR: 1.51, 95% CI: 1.30-1.76) and presence of decorative vegetation (IRR: 1.52, 95% CI: 1.22-1.88) were associated with higher Aedes density; while being in the highest wealth tertile of household wealth (IRR: 0.78, 95% CI: 0.66-0.92), knowledge of how arboviruses are transmitted (IRR: 0.94, 95% CI: 0.89-1.00) and regular emptying of water containers by occupants (IRR: 0.79, 95% CI: 0.67-0.92) were associated with lower Aedes density. CONCLUSIONS: Our study addresses the complexities of arbovirus vectors of global significance at the interface between human and mosquito populations. Our results point to several predictors of Aedes mosquito vector density in countries with co-circulation of multiple Aedes-borne viruses, and point to modifiable risk factors that may be useful for disease prevention and control.

Spatial Distribution and Burden of Emerging Arboviruses in French Guiana.

Despite the health, social and economic impact of arboviruses in French Guiana, very little is known about the extent to which infection burden is shared between individuals. We conducted a large multiplexed serological survey among 2697 individuals from June to October 2017. All serum samples were tested for IgG antibodies against DENV, CHIKV, ZIKV and MAYV using a recombinant antigen-based microsphere immunoassay with a subset further evaluated through anti-ZIKV microneutralization tests. The overall DENV seroprevalence was estimated at 73.1% (70.6-75.4) in the whole territory with estimations by serotype at 68.9% for DENV-1, 38.8% for DENV-2, 42.3% for DENV-3, and 56.1% for DENV-4. The overall seroprevalence of CHIKV, ZIKV and MAYV antibodies was 20.3% (17.7-23.1), 23.3% (20.9-25.9) and 3.3% (2.7-4.1), respectively. We provide a consistent overview of the burden of emerging arboviruses in French Guiana, with useful findings for risk mapping, future prevention and control programs. The majority of the population remains susceptible to CHIKV and ZIKV, which could potentially facilitate the risk of further re-emergences. Our results underscore the need to strengthen MAYV surveillance in order to rapidly detect any substantial changes in MAYV circulation patterns.

Social Stressors, Arboviral Infection, and Immune Dysregulation in the Coastal Lowland Region of Ecuador: A Mixed Methods Approach in Ecological Perspective.

Aedes aegypti, the mosquito that transmits arboviral diseases such as dengue (DENV), chikungunya (CHIKV), and Zika viruses (ZIKV), is present in tropical and subtropical regions of the world. Individuals at risk of mosquito-borne disease (MBD) in the urban tropics face daily challenges linked to their socio-environment conditions, such as poor infrastructure, poverty, crowding, and limited access to adequate healthcare. These daily demands induce chronic stress events and dysregulated immune responses. We sought to investigate the role of socio-ecologic risk factors in distress symptoms and their impact on biological responses to MBD in Machala, Ecuador. Between 2017 and 2019, individuals (≥ 18 years) with suspected arbovirus illness (DENV, ZIKV, and CHIKV) from sentinel clinics were enrolled (index cases, N = 28). Cluster investigations of the index case households and people from four houses within a 200-m radius of index home (associate cases, N = 144) were conducted (total N = 172). Hair samples were collected to measure hair cortisol concentration (HCC) as a stress biomarker. Blood samples were collected to measure serum cytokines concentrations of IL-10, IL-8, TNF-α, and TGF-ß. Univariate analyses were used to determine the association of socio-health metrics related to perceived stress scores (PSS), HCC, and immune responses. We found that housing conditions influence PSS and HCC levels in individuals at risk of MBD. Inflammatory cytokine distribution was associated with the restorative phase of immune responses in individuals with low-moderate HCC. These data suggest that cortisol may dampen pro-inflammatory responses and influence activation of the restorative phase of immune responses to arboviral infections.

COVID-19 and its impact on the control of Aedes (Stegomyia) aegypti mosquito and epidemiological surveillance of arbovirus infections.

In American countries, simultaneously with the coronavirus disease 2019 (COVID-19) pandemic, epidemics caused by different arboviruses (dengue, chikungunya and Zika viruses) are occurring. In Mexico, several of the strategies to control the Aedes aegypti mosquito, which transmits arboviruses, involve the interaction of health personnel with the community. Due to the COVID-19 pandemic, social distancing and home confinement measures have been implemented. To obey these measures and avoid the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission, the National Center for Preventive Programs and Disease Control (CENAPRECE) has presented the vector control strategy in the scenario of simultaneous dengue and COVID-19 transmission in Mexico. In this work, we mention the routine comprehensive mosquito control measures and describe the adaptations that have been made. Furthermore, we discuss the relevance of medical personnel training and supervision, especially focusing on the similarity of symptoms between both pathologies.

En países americanos, simultáneas a la pandemia de enfermedad por coronavirus 2019 (COVID-19) se están dando epidemias ocasionadas por diferentes arbovirus (del dengue, chikunguña y virus del Zika). En México, varias de las estrategias para control del mosquito Aedes aegypti, transmisor de arbovirus, involucran la interacción del personal salubrista y los moradores. Debido a la pandemia de COVID-19 se han implementado medidas de distanciamiento social y resguardo domiciliario. Para respetar estas medidas y evitar riesgo de contagio por coronavirus 2 del síndrome respiratorio agudo grave (SARS-CoV-2), el Centro Nacional de Programas Preventivos y Control de Enfermedades (CENAPRECE) ha presentado la estrategia de control de vectores en el escenario de transmisión simultánea por dengue y COVID-19 en México. En este trabajo mencionamos las medidas habituales de manejo integral de mosquito y mencionamos las adaptaciones realizadas. De igual forma, discutimos la relevancia de la capacitación y la supervisión al personal médico, esto debido a la similitud entre la sintomatología entre ambas patologías.

The application of spectroscopy techniques for diagnosis of malaria parasites and arboviruses and surveillance of mosquito vectors: A systematic review and critical appraisal of evidence.

CONCLUSIONS/SIGNIFICANCE: The potential of RS as a surveillance tool for malaria and arbovirus vectors and MIRS for the diagnosis and surveillance of arboviruses is yet to be assessed. NIRS capacity as a surveillance tool for malaria and arbovirus vectors should be validated under field conditions, and its potential as a diagnostic tool for malaria and arboviruses needs to be evaluated. It is recommended that all 3 techniques evaluated simultaneously using multiple machine learning techniques in multiple epidemiological settings to determine the most accurate technique for each application. Prior to their field application, a standardised protocol for spectra collection and data analysis should be developed. This will harmonise their application in multiple field settings allowing easy and faster integration into existing disease control platforms. Ultimately, development of rapid and cost-effective point-of-care diagnostic tools for malaria and arboviruses based on spectroscopy techniques may help combat current and future outbreaks of these infectious diseases.

COVID-19 y su impacto en el control del mosquito Aedes (Stegomyia) aegypti y la vigilancia epidemiológica de infecciones por arbovirus / COVID-19 and its impact on the control of Aedes (Stegomyia) aegypti mosquito and the epidemiological surveillance of arbovirus infections

Resumen En países americanos, simultáneas a la pandemia de enfermedad por coronavirus 2019 (COVID-19) se están dando epidemias ocasionadas por diferentes arbovirus (del dengue, chikunguña y virus del Zika). En México, varias de las estrategias para control del mosquito Aedes aegypti, transmisor de arbovirus, involucran la interacción del personal salubrista y los moradores. Debido a la pandemia de COVID-19 se han implementado medidas de distanciamiento social y resguardo domiciliario. Para respetar estas medidas y evitar riesgo de contagio por coronavirus 2 del síndrome respiratorio agudo grave (SARS-CoV-2), el Centro Nacional de Programas Preventivos y Control de Enfermedades (CENAPRECE) ha presentado la estrategia de control de vectores en el escenario de transmisión simultánea por dengue y COVID-19 en México. En este trabajo mencionamos las medidas habituales de manejo integral de mosquito y mencionamos las adaptaciones realizadas. De igual forma, discutimos la relevancia de la capacitación y la supervisión al personal médico, esto debido a la similitud entre la sintomatología entre ambas patologías.

Abstract Countries of Latin America are dealing with a simultaneous COVID-19 and vector borne disease (VBDs, Dengue, Zika and Chikungunya) outbreaks. In Mexico, certain activities to control Aedes aegypti mosquito (the main VBDs vector) comprise community participation through the interaction between householders and vector control personnel. Preventive measures against COVID-19 include social distancing and stay-at-home strategy, to obey these policies, and reduce the risk of infection, the National Center for Preventive Programs and Disease Control of Mexico (CENAPRECE) has adapted the vector control approaches in the country. In this paper we mention routine prevention and control activities to control mosquitoes and show the adapted measures. Because, a number of symptoms of the COVID-19 and dengue fever overlap with each other, we also discuss the relevance of accurate disease surveillance and medic’s training and supervision.

O uso de uma plataforma virtual para mobilização social no enfrentamento de arboviroses e controle do Aedes aegypti / The use of a virtual platform for social mobilization in the confrontation of arboviruses and control of Aedes aegypti / El uso de una plataforma virtual para la movilización social para combatir los arbovirus y el control de Aedes aegypti

A mobilização social para o enfrentamento da dengue, zika, chikungunya e controle do Aedes aegypti tem sido um desafio no país. Esse artigo apresenta o processo de elaboração de uma plataforma virtual, incluindo a composição do seu acervo e a análise exploratória do seu uso, como ferramenta, numa proposta de mobilização social que envolve a criação de comitês populares nos territórios para o enfrentamento das três doenças e vetor. A construção da plataforma considerou: facilidade para usuário; acesso; armazenamento de material; interatividade e banco para monitoramento de dados. A seleção do acervo baseou-se em critérios: técnico, referente à fonte e autoria; acurácia, concordância entre informação e evidência em saúde; e legibilidade, garantindo a compreensão por diferentes grupos. A análise exploratória utilizou o banco de dados da plataforma. Os resultados apontaram a plataforma como uma ferramenta que pode contribuir com a comunicação e informação em saúde nessa proposta de mobilização social.

Social mobilization for dengue, zika and chikungunya prevention and control of Aedes aegypti has been a challenge in the country. This paper presents the process of elaboration of a virtual platform, including the composition of its collection and the exploratory analysis of its use, as a tool in a social mobilization proposal that encompasses the creation of popular committees in the territories for the confrontation of the three diseases and vector. The construction of the platform considered: ease of use; access; material storage; interactivity and database for data monitoring. The selection of the collection was based on the following criteria: technical, considering source and authorship; accuracy, regarding the agreement between health information and evidence; legibility, ensuring the understanding by different groups. The exploratory analysis used the platform database. The results showed the platform as a tool which can contribute to health communication and information in this proposal of social mobilization.

La movilización social para combatir el dengue, zika, chikungunya y control de Aedes ha sido un desafío. Este artículo presenta el proceso de elaboración de una plataforma virtual, que incluye la composición de su acervo y el análisis exploratorio de su uso, como herramienta en una propuesta de movilización social que implica la creación de comités populares en los territorios para enfrentar las enfermedades y el vector. La construcción de la plataforma consideró: facilidad para usuario; acceso; almacenamiento de material; interactividad y bases de datos para el monitoreo. La selección del acervo se basó en criterios: técnico, con fuente y autoría; precisión, concordancia entre información y evidencia en salud; legibilidad, para garantizar la comprensión por diferentes grupos. El análisis utilizó datos de la plataforma. Los resultados mostraron que la plataforma puede ser una herramienta para contribuir a la comunicación e información de salud en esta propuesta de movilización social.

Reflexões e futuro / Coleção COVID-19 / Reflections and future / COVID-19 Collection

A partir dos desafios para a efetivação do direito à saúde, o Volume 6 ­ Reflexões e Futuro ­ apresenta debates relacionados às questões ambientais, urbanas, das relações humano-natureza, das arboviroses ­ que juntos contribuem para a análise da conformação do futuro pós-pandemia. Nessa esteira seguem análises relacionadas à saúde pública, à sociedade brasileira, à infoestrutura como apoio às decisões estratégicas e a avaliação, como dispositivo potente para a gestão. Ainda em sede de desafios, o livro aborda a Vigilância Sanitária como elemento primordial para o enfrentamento das emergências em saúde pública e nesse escopo se insere o Programa Nacional de Imunizações (PNI), do Brasil. À títulos comparativos, há narrativas acerca do enfrentamento da pandemia nos países de língua portuguesa, especialmente Portugal, bem como no Canadá e no Quebec possibilitando aprendizados com as experiências de outros sistemas universais. A abordagem acerca das políticas governamentais de compras públicas, da imagem do SUS nos contextos, nas narrativas e para as pessoas são encerradas com reflexões sobre a cobertura sanitária enquanto valor e a reforma sanitária brasileira como necessidade atual. Ainda que esse levante editorial se encerre, por ora, no volume 6 da Coleção COVID-19, a pandemia continua e outros tantos elementos poderão ser percebidos, contextualizados e merecerão registro. O Conass envida agradecimentos aos que estiveram empenhados em registrar seus diferentes campos de observação: gestores, auditores, ministros, médicos, pesquisadores, farmacêuticos, cientistas sociais, juízes, antropólogos, promotores, advogados, cientistas de dados, administradores, professores, comunicadores e todos que contribuíram com a análise e possíveis aperfeiçoamentos da gestão estadual do SUS no enfrentamento das emergências sanitárias.

Assessment of the susceptibility status of Aedes aegypti (Diptera: Culicidae) populations to pyriproxyfen and malathion in a nation-wide monitoring of insecticide resistance performed in Brazil from 2017 to 2018.

BACKGROUND: Chemical mosquito control using malathion has been applied in Brazil since 1985. To obtain chemical control effectiveness, vector susceptibility insecticide monitoring is required. This study aimed to describe bioassay standardizations and determine the susceptibility profile of Ae. aegypti populations to malathion and pyriproxyfen, used on a national scale in Brazil between 2017 and 2018, and discuss the observed impacts in arbovirus control. METHODS: The diagnostic-doses (DD) of pyriproxyfen and malathion were determined as the double of adult emergence inhibition (EI) and lethal doses for 99% of the Rockefeller reference strain, respectively. To monitor natural populations, sampling was performed in 132 Brazilian cities, using egg traps. Colonies were raised in the laboratory for one or two generations (F1 or F2) and submitted to susceptibility tests, where larvae were exposed to the pyriproxyfen DD (0.03 µg/l) and adults, to the malathion DD determined in the present study (20 µg), in addition to the one established by the World Health Organization (WHO) DD (50 µg) in a bottle assay. Dose-response (DR) bioassays with pyriproxyfen were performed on populations that did not achieve 98% EI in the DD assays. RESULTS: Susceptibility alterations to pyriproxyfen were recorded in six (4.5%) Ae. aegypti populations from the states of Bahia and Ceará, with Resistance Ratios (RR95) ranging from 1.51 to 3.58. Concerning malathion, 73 (55.3%) populations distributed throughout the country were resistant when exposed to the local DD 20 µg/bottle. On the other hand, no population was resistant, and only 10 (7.6%) populations in eight states were considered as exhibiting decreased susceptibility (mortality ratios between 90 and 98%) when exposed to the WHO DD (50 µg/bottle). CONCLUSIONS: The feasibility of conducting an insecticide resistance monitoring action on a nation-wide scale was confirmed herein, employing standardized and strongly coordinated sampling methods and laboratory bioassays. Brazilian Ae. aegypti populations exhibiting decreased susceptibility to pyriproxyfen were identified. The local DD for malathion was more sensitive than the WHO DD for early decreased susceptibility detection.

Climate change could shift disease burden from malaria to arboviruses in Africa.

Malaria is a long-standing public health problem in sub-Saharan Africa, whereas arthropod-borne viruses (arboviruses) such as dengue and chikungunya cause an under-recognised burden of disease. Many human and environmental drivers affect the dynamics of vector-borne diseases. In this Personal View, we argue that the direct effects of warming temperatures are likely to promote greater environmental suitability for dengue and other arbovirus transmission by Aedes aegypti and reduce suitability for malaria transmission by Anopheles gambiae. Environmentally driven changes in disease dynamics will be complex and multifaceted, but given that current public efforts are targeted to malaria control, we highlight Ae aegypti and dengue, chikungunya, and other arboviruses as potential emerging public health threats in sub-Saharan Africa.